6,13-dihalogen-5,14-dihydropentacene derivative and method for producing 6,13-substituted-5,14-dihydropentacene derivative using same

ABSTRACT

The present invention provides a 6,13-dihalogen-5,14-dihydropentacene derivative and a method for production thereof. Compounds (b) and (c) are reacted through cross-coupling reaction in the presence of a metal compound and a lithiating agent to synthesize compound (d), which is then halogenated to thereby obtain a 6,13-dihalogen-5,14-dihydropentacene derivative (compound (e)). 
                         
[wherein X 1  and X 2  are each a halogen atom, and R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9  and R 10  are each a hydrogen atom, an optionally substituted C 1 -C 20  hydrocarbon group, etc.]

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a National Stage application of PCT/JP2011/055089,filed Mar. 4, 2011, which claims priority from Japanese application JP2010-047726, filed Mar. 4, 2010.

TECHNICAL FIELD

The present invention relates to a 6,13-dihalogen-5,14-dihydropentacenederivative and a method for producing a 6,13-substituted5,14-dihydropentacene derivative using the same. The present inventionalso relates to a method for producing a 6,13-substituted pentacenederivative.

BACKGROUND ART

Polyacene compounds including pentacene have now received attention asorganic electronic materials for organic semiconductors or organicelectroconductive materials, etc. However, it is not easy to introduce asubstituent of any type at any position of the side chain on thepolyacene skeleton, and hence there has been a demand for achievingsimpler production of a desired compound.

For introduction of substituents at the 6- and 13-positions of thepentacene skeleton, the method of Maulding et al. has been known(Non-patent Document 1: D. R. Maulding, and Bernard G Roberts“Electronic absorption and fluorescence of phenylethynyl-substitutedacenes” J. Org. Chem., 34, 1969, pp 1734). In the method of Maulding etal., pentacenequinone is reacted with Grignard reagents to therebyintroduce substituted alkynylene groups at the 6- and 13-positions ofthe pentacene skeleton (see the scheme shown below).

Moreover, for synthesis of a pentacene derivative using pentacenequinoneas a starting compound, the method of Miller et al. has also been known(Non-patent Document 2: Kaur, W. Jia, R. P. Kopreski, S. Selvarasah, M.R. Dokmeci, C. Pramanik, N. E. McGruer, G P. Miller “Substituent Effectsin Pentacenes: Gaining Control over HOMO-LUMO Gaps and PhotooxidativeResistances” J. Am. Chem. Soc., 130, 2008, pp 16274). In the method ofMiller et al., pentacenequinone is reduced to convert its 6- and13-positions into hydroxy groups, which are then replaced withalkylthiol groups, finally followed by aromatization with chloranil tothereby introduce alkylthio groups (see the scheme shown below).

However, these conventional methods have problems in that desiredcompounds cannot be obtained in high yields or are difficult to isolatebecause side reactions may occur in these methods.

For example, during reaction between pentacenequinone and thienylgroups, there is a risk that substituents on the thienyl groups willcause a reaction by which two thienyl groups are transferred to the sameside during diol formation (Non-patent Document 3: N. Vets, M. Smet, W.Dehaen, “Reduction versus Rearrangement of6,13-Dihydro-6,13-diarylpentacene-6,13-diols Affording 6,13- and13,13-Substituted Pentacene Derivatives, Substituted Nephtacaenes andPentacenes” SYNLETT 2005, pp 0217).

Moreover, during reaction between pentacenequinone and phenyl Grignard,1,4-addition reaction will occur that does not target the carbonyls atthe 6- and 13-positions of pentacene, but attacks their adjacent rings,so that a phenyl group is attached to the second ring (Non-patentDocument 4: C. F. H. Allen, A. Bell “Action of Grignard Reagents onCertain Pentacenequinones, 6,13-Diphenylpentacene” J. Am. Chem. Soc.,64, 1942 pp 1253).

Furthermore, it is well known that upon reaction with alkyllithium oralkyl Grignard reagents in an attempt to introduce alkyl groups at the6- and 13-positions of pentacene, isomerization reaction will occur anddesired compounds cannot be obtained at all. In this conventional methodstarting with pentacenequinone, nobody has succeeded in introducingalkyl groups.

In contrast, the inventors of the present invention have proposed a newapproach to form the pentacene skeleton, which involves synthesis of astarting material having alkyl substituents and the subsequent couplingreaction with a diiodo compound. The inventors of the present inventionhave suggested that the above problems associated with alkyl groups canbe avoided, and have reported that alkyl groups can actually beintroduced at the 6- and 13-positions of pentacene (Non-patent Document5: T. Takahashi, K. Kashima, S. Li, K. Nakajima, K. Kanno “Isolation of6,13-Dipropylpentacene and its tautomerization” J. Am. Chem. Soc., 129,2007, pp 15752).

PRIOR ART DOCUMENTS Non-Patent Documents

-   Non-patent Document 1: D. R. Maulding, and Bernard G Roberts    “Electronic absorption and fluorescence of phenylethynyl-substituted    acenes” J. Org. Chem., 34, 1969, pp 1734-   Non-patent Document 2: Kaur, W. Jia, R. P. Kopreski, S.    Selvarasah, M. R. Dokmeci, C. Pramanik, N. E. McGruer, G P. Miller    “Substituent Effects in Pentacenes: Gaining Control over HOMO-LUMO    Gaps and Photooxidative Resistances” J. Am. Chem. Soc., 130, 2008,    pp 16274-   Non-patent Document 3: N. Vets, M. Smet, W. Dehaen, “Reduction    versus Rearrangement of 6,13-Dihydro-6,13-diarylpentacene-6,13-diols    Affording 6,13- and 13,13-Substituted Pentacene Derivatives,    Substituted Nephtacaenes and Pentacenes” SYNLETT 2005, pp 0217-   Non-patent Document 4: C. F. H. Allen, A. Bell “Action of Grignard    Reagents on Certain Pentacenequinones, 6,13-Diphenylpentacene” J.    Am. Chem. Soc., 64, 1942 pp 1253-   Non-patent Document 5: T. Takahashi, K. Kashima, S. Li, K.    Nakajima, K. Kanno “Isolation of 6,13-Dipropylpentacene and its    tautomerization” J. Am. Chem. Soc., 129, 2007, pp 15752

SUMMARY OF THE INVENTION Problem to be Solved by the Invention

As described above, there has been a demand for a method for producing apentacene derivative having substituents at the 6- and 13-positions ofthe pentacene skeleton in a simpler manner with high selectivity.

Means to Solve the Problem

As described above, the inventors of the present invention have alreadyreported that coupling reaction with a diiodo compound allows thesolution of problems in prior art techniques and enables theintroduction of alkyl groups at the 6- and 13-positions of pentacene.However, in this method, substituents are introduced into a startingmaterial before the pentacene skeleton is formed. If substituents of anytype can be introduced after the pentacene skeleton is formed, such anapproach will be simpler as a production method and will have a widerrange of applications.

As a result of extensive and intensive efforts made to solve theproblems stated above, the inventors of the present invention have firstfound that substituents of various types can be introduced with highselectivity at the 6- and 13-positions of a 5,14-dihydropentacenecompound when a 6,13-dihalogenated dihydropentacene derivative whose 6-and 13-positions are substituted with halogen atoms is synthesized andreacted with various organometallic compounds through cross-couplingreaction. The inventors of the present invention have further found thata pentacene derivative having substituents of any type at the 6- and13-positions can be produced with high selectivity upon aromatization ofthe resulting 6,13-substituted 5,14-dihydropentacene derivative. Thesefindings led to the completion of the present invention.

Namely, as shown below, the present invention relates to a6,13-dihalogen-5,14-dihydropentacene derivative and a method forproducing a 6,13-substituted 5,14-dihydropentacene derivative using thesame, as well as a method for producing a 6,13-substituted pentacenederivative, etc.

[1] A 6,13-dihalogen-5,14-dihydropentacene derivative represented by thefollowing formula (I):

[wherein X¹ and X², which may be the same or different, are eachindependently a halogen atom, and R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ andR¹⁰, which may be the same or different, are each independently ahydrogen atom; an optionally substituted C₁-C₂₀ hydrocarbon group; anoptionally substituted C₁-C₂₀ alkoxy group; an optionally substitutedC₆-C₂₀ aryloxy group; an optionally substituted C₁-C₂₀ alkoxycarbonylgroup; an optionally substituted C₆-C₂₀ aryloxycarbonyl group; anoptionally substituted carbamoyl group; an optionally substituted aminogroup or an optionally substituted silyl group, wherein if thehydrocarbon group, the alkoxy group, the aryloxy group, thealkoxycarbonyl group, the aryloxycarbonyl group, the carbamoyl group,the amino group or the silyl group has a substituent(s), thesubstituent(s) is/are selected from the group consisting of a C₁-C₁₀hydrocarbon group, a C₁-C₁₀ alkoxy group, a C₆-C₁₂ aryloxy group, anamino group, a hydroxyl group, a halogen atom and a silyl group].[2] The derivative according to [1] above, wherein X¹ and X² are each aniodine atom.[3] The derivative according to [1] or [2] above, wherein R¹, R², R³,R⁴, R⁵, R⁶, R⁷; R⁸, R⁹ and R¹⁰, which may be the same or different, areeach independently a hydrogen atom; an optionally substituted C₁-C₂₀alkyl group; an optionally substituted C₆-C₂₀ aryl group or anoptionally substituted silyl group.[4] The derivative according to any one of [1] to [3] above, wherein R¹,R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰ are each a hydrogen atom.[5] A method for producing a 6,13-substituted 5,14-dihydropentacenederivative represented by the following formula (II):

[wherein A¹ and A², which may be the same or different, are eachindependently an optionally substituted C₁-C₂₀ hydrocarbon group; anoptionally substituted heteroaryl group; an optionally substitutedC₁-C₂₀ alkoxy group; an optionally substituted C₆-C₂₀ aryloxy group; anoptionally substituted C₁-C₂₀ alkoxycarbonyl group; an optionallysubstituted C₆-C₂₀ aryloxycarbonyl group; an optionally substitutedcarbamoyl group; an optionally substituted amino group or an optionallysubstituted silyl group, wherein if the hydrocarbon group, theheteroaryl group, the alkoxy group, the aryloxy group, thealkoxycarbonyl group, the aryloxycarbonyl group, the carbamoyl group,the amino group or the silyl group has a substituent(s), thesubstituent(s) is/are selected from the group consisting of a C₁-C₁₀hydrocarbon group, a C₁-C₁₀ alkoxy group, a C₆-C₁₂ aryloxy group, anamino group, a hydroxyl group, a halogen atom and a silyl group, and

R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰, which may be the same ordifferent, are each independently a hydrogen atom; an optionallysubstituted C₁-C₂₀ hydrocarbon group; an optionally substituted C₁-C₂₀alkoxy group; an optionally substituted C₆-C₂₀ aryloxy group; anoptionally substituted C₁-C₂₀ alkoxycarbonyl group; an optionallysubstituted C₆-C₂₀ aryloxycarbonyl group; an optionally substitutedcarbamoyl group; an optionally substituted amino group or an optionallysubstituted silyl group, wherein if the hydrocarbon group, the alkoxygroup, the aryloxy group, the alkoxycarbonyl group, the aryloxycarbonylgroup, the carbamoyl group, the amino group or the silyl group has asubstituent(s), the substituent(s) is/are selected from the groupconsisting of a C₁-C₁₀ hydrocarbon group, a C₁-C₁₀ alkoxy group, aC₆-C₁₂ aryloxy group, an amino group, a hydroxyl group, a halogen atomand a silyl group],

said method comprising the step of reacting a6,13-dihalogen-5,14-dihydropentacene derivative represented by thefollowing formula (I):

[wherein X¹ and X², which may be the same or different, are eachindependently a halogen atom, and R¹, R², R³, R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰are the same as defined in formula (II)]with an organometallic compound comprising A¹ or A² as defined informula (II) in the presence of a transition metal catalyst.[6] The method according to [5] above, wherein the organometalliccompound is selected from the group consisting of an organolithiumcompound, an organomagnesium compound, an organoaluminum compound, anorganozinc compound, an organoboron compound and an organosilylcompound.[7] The method according to [5] or [6] above, wherein the organometalliccompound is any of compounds represented by formulae (1) to (6):RLi  (1)RMgY  (2)R₃Al  (3)RZnY  (4)RBY₂  (5)RSiR′₃  (6)[wherein each R, which may be the same or different, is independently A¹or A² as defined in formula (II), each Y, which may be the same ordifferent, is independently a halogen atom or a hydroxy group, and R′ isa C₁-C₁₀ alkyl group].[8] The method according to any one of [5] to [7] above, wherein thetransition metal catalyst comprises a nickel complex or a palladiumcomplex.[9] The method according to any one of [5] to [8] above, wherein A¹ andA², which may be the same or different, are each independently anoptionally substituted C₁-C₂₀ alkyl group, an optionally substitutedC₂-C₂₀ alkenyl group, an optionally substituted C₂-C₂₀ alkynyl group, anoptionally substituted C₆-C₂₀ aryl group or an optionally substitutedheteroaryl group.[10] The method according to any one of [5] to [9] above, wherein X¹ andX² are each an iodine atom.[11] The method according to any one of [5] to [10] above, wherein R¹,R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰, which may be the same ordifferent, are each independently a hydrogen atom; an optionallysubstituted C₁-C₂₀ alkyl group; an optionally substituted C₆-C₂₀ arylgroup or an optionally substituted silyl group.[12] The method according to any one of [5] to [11] above, wherein R¹,R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰ are each a hydrogen atom.[13] A method for producing a 6,13-substituted pentacene derivativerepresented by the following formula (III):

[wherein A¹ and A², which may be the same or different, are eachindependently an optionally substituted C₁-C₂₀ hydrocarbon group; anoptionally substituted heteroaryl group; an optionally substitutedC₁-C₂₀ alkoxy group; an optionally substituted C₆-C₂₀ aryloxy group; anoptionally substituted C₁-C₂₀ alkoxycarbonyl group; an optionallysubstituted C₆-C₂₀ aryloxycarbonyl group; an optionally substitutedcarbamoyl group; an optionally substituted amino group or an optionallysubstituted silyl group, wherein if the hydrocarbon group, the alkoxygroup, the aryloxy group, the amino group or the silyl group has asubstituent(s), the substituent(s) is/are selected from the groupconsisting of a C₁-C₁₀ hydrocarbon group, a heteroaryl group, a C₁-C₁₀alkoxy group, a C₆-C₁₂ aryloxy group, an alkoxycarbonyl group, anaryloxycarbonyl group, a carbamoyl group, an amino group, a hydroxylgroup, a halogen atom and a silyl group, and

R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰, which may be the same ordifferent, are each independently a hydrogen atom; an optionallysubstituted C₁-C₂₀ hydrocarbon group; an optionally substituted C₁-C₂₀alkoxy group; an optionally substituted C₆-C₂₀ aryloxy group; anoptionally substituted C₁-C₂₀ alkoxycarbonyl group; an optionallysubstituted C₆-C₂₀ aryloxycarbonyl group; an optionally substitutedcarbamoyl group; an optionally substituted amino group or an optionallysubstituted silyl group, wherein if the hydrocarbon group, the alkoxygroup, the aryloxy group, the alkoxycarbonyl group, the aryloxycarbonylgroup, the carbamoyl group, the amino group or the silyl group has asubstituent(s), the substituent(s) is/are selected from the groupconsisting of a C₁-C₁₀ hydrocarbon group, a C₁-C₁₀ alkoxy group, aC₆-C₁₂ aryloxy group, an amino group, a hydroxyl group, a halogen atomand a silyl group],

said method comprising the steps of:

reacting a 6,13-dihalogen-5,14-dihydropentacene derivative representedby the following formula (I):

[wherein X¹ and X², which may be the same or different, are eachindependently a halogen atom, and R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ andR¹⁰ are the same as defined in formula (III)]with an organometallic compound comprising A¹ or A² as defined informula (III) in the presence of a transition metal catalyst; and

aromatizing the compound obtained in the above step in the presence of adehydrogenation reagent.

[14] The method according to [13] above, wherein the organometalliccompound is selected from the group consisting of an organolithiumcompound, an organomagnesium compound, an organoaluminum compound, anorganozinc compound, an organoboron compound and an organosilylcompound.[15] The method according to [13] or [14] above, wherein theorganometallic compound is any of compounds represented by formulae (1)to (6):RLi  (1)RMgY  (2)R₃Al  (3)RZnY  (4)RBY₂  (5)RSiR′₃  (6)[wherein each R, which may be the same or different, is independently A¹or A² as defined in formula (III), each Y, which may be the same ordifferent, is independently a halogen atom or a hydroxy group, and R′ isa C₁-C₁₀ alkyl group].[16] The method according to any one of [13] to [15] above, wherein thetransition metal catalyst comprises a nickel complex or a palladiumcomplex.[17] The method according to any one of [13] to [16] above, wherein A¹and A², which may be the same or different, are each independently anoptionally substituted C₁-C₂₀ alkyl group, an optionally substitutedC₂-C₂₀ alkenyl group, an optionally substituted C₂-C₂₀ alkynyl group, anoptionally substituted C₆-C₂₀ aryl group or an optionally substitutedheteroaryl group.[18] The method according to any one of [13] to [17] above, wherein X¹and X² are each an iodine atom.[19] The method according to any one of [13] to [18] above, wherein R¹,R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰, which may be the same ordifferent, are each independently a hydrogen atom; an optionallysubstituted C₁-C₂₀ alkyl group; an optionally substituted C₆-C₂₀ arylgroup or an optionally substituted silyl group.[20] The method according to any one of [13] to [19] above, wherein R¹,R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰ are each a hydrogen atom.[21] A complex compound represented by the following formula (IV):

[wherein X¹ and X², which may be the same or different, are eachindependently a halogen atom, R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ andR¹⁰, which may be the same or different, are each independently ahydrogen atom; an optionally substituted C₁-C₂₀ hydrocarbon group; anoptionally substituted C₁-C₂₀ alkoxy group; an optionally substitutedC₆-C₂₀ aryloxy group; an optionally substituted C₁-C₂₀ alkoxycarbonylgroup; an optionally substituted C₆-C₂₀ aryloxycarbonyl group; anoptionally substituted carbamoyl group; an optionally substituted aminogroup or an optionally substituted silyl group, wherein if thehydrocarbon group, the alkoxy group, the aryloxy group, thealkoxycarbonyl group, the aryloxycarbonyl group, the carbamoyl group,the amino group or the silyl group has a substituent(s), thesubstituent(s) is/are selected from the group consisting of a C₁-C₁₀hydrocarbon group, a C₁-C₁₀ alkoxy group, a C₆-C₁₂ aryloxy group, anamino group, a hydroxyl group, a halogen atom and a silyl group, andR^(a) and R^(b), which may be the same or different, are eachindependently a C₁-C₂₀ alkyl group or a C₆-C₂₀ aryl group].[22] A method for producing a 6,13-substituted 5,14-dihydropentacenederivative represented by the following formula (II):

[wherein A¹ and A², which may be the same or different, are eachindependently an optionally substituted C₁-C₂₀ hydrocarbon group; anoptionally substituted heteroaryl group; an optionally substitutedC₁-C₂₀ alkoxy group; an optionally substituted C₆-C₂₀ aryloxy group; anoptionally substituted C₁-C₂₀ alkoxycarbonyl group; an optionallysubstituted C₆-C₂₀ aryloxycarbonyl group; an optionally substitutedcarbamoyl group; an optionally substituted amino group or an optionallysubstituted silyl group, wherein if the hydrocarbon group, theheteroaryl group, the alkoxy group, the aryloxy group, thealkoxycarbonyl group, the aryloxycarbonyl group, the carbamoyl group,the amino group or the silyl group has a substituent(s), thesubstituent(s) is/are selected from the group consisting of a C₁-C₁₀hydrocarbon group, a C₁-C₁₀ alkoxy group, a C₆-C₁₂ aryloxy group, anamino group, a hydroxyl group, a halogen atom and a silyl group, and

R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰, which may be the same ordifferent, are each independently a hydrogen atom; an optionallysubstituted C₁-C₂₀ hydrocarbon group; an optionally substituted C₁-C₂₀alkoxy group; an optionally substituted C₆-C₂₀ aryloxy group; anoptionally substituted C₁-C₂₀ alkoxycarbonyl group; an optionallysubstituted C₆-C₂₀ aryloxycarbonyl group; an optionally substitutedcarbamoyl group; an optionally substituted amino group or an optionallysubstituted silyl group, wherein if the hydrocarbon group, the alkoxygroup, the aryloxy group, the alkoxycarbonyl group, the aryloxycarbonylgroup, the carbamoyl group, the amino group or the silyl group has asubstituent(s), the substituent(s) is/are selected from the groupconsisting of a C₁-C₁₀ hydrocarbon group, a C₁-C₁₀ alkoxy group, aC₆-C₁₂ aryloxy group, an amino group, a hydroxyl group, a halogen atomand a silyl group],

said method comprising the step of reacting a complex compoundrepresented by the following formula (IV):

[wherein X¹ and X², which may be the same or different, are eachindependently a halogen atom, R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰are the same as defined in formula (II), and R^(a) and R^(b), which maybe the same or different, are each independently a C₁-C₂₀ alkyl group ora C₆-C₂₀ aryl group]with an organometallic compound comprising A¹ or A² as defined informula (II).

Effect of the Invention

The present invention provides a 6,13-dihalogen-5,14-dihydropentacenederivative, which is a novel compound. When using the6,13-dihalogen-5,14-dihydropentacene derivative of the presentinvention, it is possible to produce 6,13-substituted5,14-dihydropentacene derivatives having substituents of various typesat the 6- and 13-positions in a simpler manner. Moreover, it is alsopossible to produce 6,13-substituted pentacene derivatives havingsubstituents of various types at the 6- and 13-positions in a simplermanner. According to the production method of the present invention, adesired compound can be produced with high selectivity. The presentinvention also provides an intermediate in the above production methodand a method for producing a 6,13-substituted 5,14-dihydropentacenederivative using the intermediate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the results of X-ray structural analysis obtained for thecomplex compound of the present invention (Example 7).

MODES FOR CARRYING OUT THE INVENTION

A detailed explanation will be given below of the dihalogenateddihydropentacene derivative of the present invention and a method forproducing a 6,13-substituted dihydropentacene derivative using the same,as well as a 6,13-substituted pentacene derivative, etc.

[1] 6,13-Dihalogen-5,14-dihydropentacene derivative

The 6,13-dihalogen-5,14-dihydropentacene derivative of the presentinvention is a compound represented by the following formula (I):

[wherein X¹ and X², which may be the same or different, are eachindependently a halogen atom, and R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ andR¹⁰, which may be the same or different, are each independently ahydrogen atom; an optionally substituted C₁-C₂₀ hydrocarbon group; anoptionally substituted C₁-C₂₀ alkoxy group; an optionally substitutedC₆-C₂₀ aryloxy group; an optionally substituted C₁-C₂₀ alkoxycarbonylgroup; an optionally substituted C₆-C₂₀ aryloxycarbonyl group; anoptionally substituted carbamoyl group; an optionally substituted aminogroup or an optionally substituted silyl group, wherein if thehydrocarbon group, the alkoxy group, the aryloxy group, thealkoxycarbonyl group, the aryloxycarbonyl group, the carbamoyl group,the amino group or the silyl group has a substituent(s), thesubstituent(s) is/are selected from the group consisting of a C₁-C₁₀hydrocarbon group, a C₁-C₁₀ alkoxy group, a C₆-C₁₂ aryloxy group, anamino group, a hydroxyl group, a halogen atom and a silyl group].

The 6,13-dihalogen-5,14-dihydropentacene derivative of the presentinvention has halogen atoms at the 6- and 13-positions and has anyadditional substituents R¹ to R¹⁰ as side chains located at positionsother than the 5- and 14-positions. The6,13-dihalogen-5,14-dihydropentacene derivative of the present inventionis highly soluble in organic solvents as a result of dihydromodification at the 5- and 14-positions, so that substituents of anytype can be introduced with high selectivity at the 6- and 13-positionsof the 6,13-dihalogen-5,14-dihydropentacene derivative of the presentinvention.

In the context of the present invention, the “halogen atom” includesfluorine, chlorine, bromine, and iodine. Among them, bromine or iodineis preferred.

In the context of the present invention, the hydrocarbon group in the“C₁-C₂₀ hydrocarbon group” may be saturated or unsaturated noncyclic ormay be saturated or unsaturated cyclic. When the C₁-C₂₀ hydrocarbongroup is noncyclic, it may be linear or branched. The “C₁-C₂₀hydrocarbon group” includes a C₁-C₂₀ alkyl group, a C₂-C₂₀ alkenylgroup, a C₂-C₂₀ alkynyl group, a C₄-C₂₀ alkyldienyl group, a C₆-C₁₈ arylgroup, a C₇-C₂₀ alkylaryl group, a C₇-C₂₀ arylalkyl group, a C₄-C₂₀cycloalkyl group, a C₄-C₂₀ cycloalkenyl group, a (C₃-C₁₀cycloalkyl)C₁-C₁₀ alkyl group and so on.

In the context of the present invention, the “C₁-C₂₀ alkyl group” ispreferably a C₁-C₁₂ alkyl group, more preferably a C₁-C₁₀ alkyl group,and even more preferably a C₁-C₆ alkyl group. Examples of such an alkylgroup include, but are not limited to, methyl, ethyl, propyl, isopropyl,n-butyl, sec-butyl, tert-butyl, pentyl, hexyl, dodecanyl and so on.

In the context of the present invention, the “C₂-C₂₀ alkenyl group” ispreferably a C₂-C₁₀ alkenyl group, and more preferably a C₂-C₆ alkenylgroup. Examples of such an alkenyl group include, but are not limitedto, vinyl, allyl, propenyl, isopropenyl, 2-methyl-1-propenyl,2-methylallyl, 2-butenyl and so on.

In the context of the present invention, the “C₂-C₂₀ alkynyl group” ispreferably a C₂-C₁₀ alkynyl group, and more preferably a C₂-C₆ alkynylgroup. Examples of such an alkynyl group include, but are not limitedto, ethynyl, propynyl, butynyl and so on. Other examples include, butare not particularly limited to, alkynyl groups having a silyl group(e.g., a triisopropylsilyl group) as a substituent.

In the context of the present invention, the “C₄-C₂₀ alkyldienyl group”is preferably a C₄-C₁₀ alkyldienyl group, and more preferably a C₄-C₆alkyldienyl group. Examples of such an alkyldienyl group include, butare not limited to, 1,3-butadienyl and so on.

In the context of the present invention, the “C₆-C₁₈ aryl group” ispreferably a C₆-C₁₂ aryl group. Examples of such an aryl group include,but are not limited to, phenyl, 1-naphthyl, 2-naphthyl, indenyl,biphenylyl, anthryl, phenanthryl and so on.

In the context of the present invention, the “C₇-C₂₀ alkylaryl group” ispreferably a C₇-C₁₂ alkylaryl group. Examples of such an alkylaryl groupinclude, but are not limited to, o-tolyl, m-tolyl, p-tolyl, 2,3-xylyl,2,4-xylyl, 2,5-xylyl, o-cumenyl, m-cumenyl, p-cumenyl, mesityl and soon.

In the context of the present invention, the “C₇-C₂₀ arylalkyl group” ispreferably a C₇-C₁₂ arylalkyl group. Examples of such an arylalkyl groupinclude, but are not limited to, benzyl, phenethyl, diphenylmethyl,triphenylmethyl, 1-naphthylmethyl, 2-naphthylmethyl, 2,2-diphenylethyl,3-phenylpropyl, 4-phenylbutyl, 5-phenylpentyl and so on.

In the context of the present invention, the “C₄-C₂₀ cycloalkyl group”is preferably a C₄-C₁₀ cycloalkyl group. Examples of such a cycloalkylgroup include, but are not limited to, cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl and so on.

In the context of the present invention, the “C₄-C₂₀ cycloalkenyl group”is preferably a C₄-C₁₀ cycloalkenyl group. Examples of such acycloalkenyl group include, but are not limited to, cyclopropenyl,cyclobutenyl, cyclopentenyl, cyclohexenyl and so on.

In the context of the present invention, the “C₁-C₂₀ alkoxy group” ispreferably a C₁-C₁₀ alkoxy group, and more preferably a C₁-C₆ alkoxygroup. Examples of the “C₁-C₂₀ alkoxy group” include, but are notlimited to, methoxy, ethoxy, propoxy, butoxy, pentyloxy and so on.

In the context of the present invention, the “C₆-C₁₈ aryloxy group” ispreferably a C₆-C₁₂ aryloxy group. Examples of such an aryloxy groupinclude, but are not limited to, phenyloxy, naphthyloxy, biphenyloxy andso on.

In the context of the present invention, the “C₁-C₂₀ alkoxycarbonylgroup” is preferably a C₁-C₁₀ alkoxycarbonyl group, and more preferablya C₁-C₆ alkoxycarbonyl group. Examples of such an alkoxycarbonyl groupinclude, but are not limited to, methoxycarbonyl, ethoxycarbonyl,2-methoxyethoxycarbonyl, t-butoxycarbonyl and so on.

In the context of the present invention, the “C₆-C₂₀ aryloxycarbonylgroup” is preferably a C₆-C₁₂ aryloxycarbonyl group, and more preferablya C₆-C₁₀ aryloxycarbonyl group. Examples of such an aryloxycarbonylgroup include, but are not limited to, phenoxycarbonyl,naphthoxycarbonyl, phenylphenoxycarbonyl and so on.

In the context of the present invention, the “heteroaryl group” is amonocyclic, polycyclic or condensed ring heteroaryl group containingone, two or three heteroatoms selected from an oxygen atom, a sulfuratom or a nitrogen atom. Particularly preferred are 5- or 6-memberedmonocyclic heteroaryl groups, as well as polycyclic heteroaryl groups inwhich these monocyclic heteroaryl groups are linked via a single bond.Examples of such a heteroaryl group include imidazolyl, pyridyl, furyl,pyrrolyl, thiophenyl, bithiophenyl and so on.

In the context of the present invention, if the hydrocarbon group, theheteroaryl group, the alkoxy group, the aryloxy group, thealkoxycarbonyl group, the aryloxycarbonyl group, the carbamoyl group,the amino group or the silyl group has a substituent(s), thesubstituent(s) is/are selected from the group consisting of a C₁-C₁₀hydrocarbon group, a C₁-C₁₀ alkoxy group, a C₆-C₁₂ aryloxy group, anamino group, a hydroxyl group, a halogen atom and a silyl group. Thenumber of these substituents may be one or two or more.

In the context of the present invention, examples of the “optionallysubstituted carbamoyl group (—C(═O)NH₂)” include, but are not limitedto, mono-C₁-C₆ alkyl-carbamoyl (e.g., methylcarbamoyl, ethylcarbamoyl),di-C₁-C₆ alkyl-carbamoyl (e.g., dimethylcarbamoyl, diethylcarbamoyl,ethylmethylcarbamoyl) and so on.

In the context of the present invention, examples of the “optionallysubstituted amino group” preferably include amino, dimethylamino,methylamino, methylphenylamino, phenylamino and so on.

In the context of the present invention, examples of the “optionallysubstituted silyl group” preferably include dimethylsilyl, diethylsilyl,trimethylsilyl, triethylsilyl, trimethoxysilyl, triethoxysilyl,diphenylmethylsilyl, triphenylsilyl, triphenoxysilyl,dimethylmethoxysilyl, dimethylphenoxysilyl, methylmethoxyphenyl,triisopropyl and so on.

In one embodiment of the present invention, it is preferred that R¹, R²,R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰, which may be the same or different,are each independently a hydrogen atom, an optionally substituted C₁-C₂₀alkyl group or an optionally substituted C₆-C₂₀ aryl group, with ahydrogen atom being particularly preferred.

The 6,13-dihalogen-5,14-dihydropentacene derivative of the presentinvention can be synthesized by combining known reactions. For example,the 6,13-dihalogen-5,14-dihydropentacene derivative of the presentinvention can be synthesized according to the synthesis scheme shownbelow:

[wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, X¹ and X² are asdefined above; each X, which may be the same or different, independentlyrepresents a halogen atom; M represents a metal of Groups 3 to 5 or thelanthanide series in the periodic table; L¹ and L², which may be thesame or different, each independently represent an anionic ligand,provided that L¹ and L² may be bridged; and Y¹ and Y², which may be thesame or different, each independently represent a leaving group].

First, compound (a) and an organometallic compound represented byL¹L²MY¹Y² are reacted in the presence of a metal compound and a halogenmolecule X₂ to obtain compound (b). Formation of a dihalogenatedcompound from a diyne compound and an organometallic compoundrepresented by L¹L²MY¹Y² can be found in, e.g., Takahashi et al.,Tetrahedron Letters, Vol. 38, No. 23, pp. 4099-4102 (1997), and thereaction proceeds under the same or equivalent conditions as found inthis document.

In the organometallic compound represented by L¹L²MY¹Y², M represents ametal of Groups 3 to 5 or the lanthanide series in the periodic table. Mis preferably a metal of Group 4 or the lanthanide series in theperiodic table, and more preferably a metal of Group 4 in the periodictable, i.e., titanium, zirconium or hafnium.

L¹ and L², which may be the same or different, each independentlyrepresent an anionic ligand. Such an anionic ligand is preferably anon-localized cyclic re-coordinated ligand, a C₁-C₂₀ alkoxy group, aC₆-C₂₀ aryloxy group or a dialkylamido group. Among them, preferred is anon-localized cyclic η⁵-coordinated ligand. Preferred examples of anon-localized cyclic η⁵-coordinated ligand include an unsubstitutedcyclopentadienyl group and a substituted cyclopentadienyl group.

Examples of a substituted cyclopentadienyl group includemethylcyclopentadienyl, ethylcyclopentadienyl,isopropylcyclopentadienyl, n-butylcyclopentadienyl,t-butylcyclopentadienyl, dimethylcyclopentadienyl,diethylcyclopentadienyl, diisopropylcyclopentadienyl,di-t-butylcyclopentadienyl, tetramethylcyclopentadienyl, indenyl,2-methylindenyl, 2-methyl-4-phenylindenyl, tetrahydroindenyl,benzoindenyl, fluorenyl, benzofluorenyl, tetrahydrofluorenyl andoctahydrofluorenyl.

In these non-localized cyclic η⁵-coordinated ligands, one or more atomsin the non-localized cyclic π system may be replaced with heteroatoms.These ligands may comprise, in addition to hydrogens, one or moreheteroatoms such as elements of Group 14 in the periodic table and/orelements of Groups 15, 16 and 17 in the periodic table.

Such a non-localized cyclic η⁵-coordinated ligand, e.g., acyclopentadienyl group may be bridged to the central metal via one ormore bridging ligands which may be cyclic. Examples of a bridging ligandinclude CH₂, CH₂CH₂, CH(CH₃)CH₂, CH(C₄H₉)C(CH₃)₂, C(CH₃)₂, (CH₃)₂Si,(CH₃)₂Ge, (CH₃)₂Sn, (C₆H₅)₂Si, (C₆H₅)(CH₃)Si, (C₆H₅)₂Ge, (C₆H₅)₂Sn,(CH₂)₄Si, CH₂Si(CH₃)₂, o-C₆H₄ or 2,2′-(C₆H₄)₂.

Y¹ and Y², which may be the same or different, each independentlyrepresent a leaving group. Examples of a leaving group include halogenatoms (e.g., F, Cl, Br, I); C₁-C₂₀ alkyl groups (e.g., a n-butyl group);C₆-C₂₀ aryl groups (e.g., a phenyl group) and so on. Among them, halogenatoms are preferred.

It should be noted that when a dihalogeno compound is used as anorganometallic compound represented by L¹L²MY¹Y², as exemplified bybis(cyclopentadienyl)dichlorozirconium;bis(methylcyclopentadienyl)dichlorozirconium;bis(butylcyclopentadienyl)dichlorozirconium;bis(indenyl)dichlorozirconium; bis(fluorenyl)dichlorozirconium;(indenyl)(fluorenyl)dichlorozirconium;bis(cyclopentadienyl)dichlorotitanium;(dimethylsilanediyl)bis(indenyl)dichlorozirconium;(dimethylsilanediyl)bis(tetrahydroindenyl)dichlorozirconium;(dimethylsilanediyl)(indenyl)dichlorozirconium;(dimethylsilanediyl)bis(2-methylindenyl)dichlorozirconium;(dimethylsilanediyl)bis(2-ethylindenyl)dichlorozirconium;(dimethylsilanediyl)bis(2-methyl-4,5-benzoindenyl)dichlorozirconium;(dimethylsilanediyl)bis(2-ethyl-4,5-benzoindenyl)dichlorozirconium;(dimethylsilanediyl)bis(2-methyl-4-phenylindenyl)dichlorozirconium;(dimethylsilanediyl)bis(2-ethyl-4-phenylindenyl)dichlorozirconium;(dimethylsilanediyl)bis(2-methyl-4,6-diisopropylindenyl)dichlorozirconium,etc., it is preferred that such a dihalogeno compound is reduced with astrong base of an alkali metal (e.g., sodium), an alkaline earth metal(e.g., magnesium) or the like or converted into a dialkyl form beforeuse.

The amount of the organometallic compound represented by L¹L²MY¹Y² to beused is preferably 0.1 to 10 moles, more preferably 0.5 to 3 moles, andeven more preferably 0.5 to 2 moles, relative to 1 mole of compound (a).

A metal compound preferred for use in the reaction is a metal compoundof Groups 4 to 15 in the periodic table. Such a metal compound may be ina salt form such as CuCl or may be an organometallic complex.

Examples of a salt used for this purpose include metal salts, asexemplified by CuX, NiX₂, PdX₂, ZnX₂, CrX₂, CrX₃, CoX₂ or BiX₃ (whereinX represents a halogen atom such as a chlorine atom, a bromine atom,etc.).

Organometallic complexes preferred for use are those in which thecentral metal of Groups 3 to 11 in the periodic table, preferably thecentral metal of Groups 6 to 11 in the periodic table is coordinatedwith ligands such as phosphine, aromatic amines (e.g., pyridine,bipyridine), halogen atoms, etc. The central metal preferably allowsso-called coordination with 4 to 6 ligands, and is more preferably ametal of Group 10 in the periodic table. Phosphine may be of any form,such as triphenylphosphine, methyldiphenylphosphine, etc. Examples oforganometallic complexes include bis(triphenylphosphine)dichloronickel,dichloro(2,2′-bipyridine)nickel, and PdCl₂(2,2′-bipyridine).Particularly desired are nickel complexes and palladium complexes, whichare used as catalysts for cross-coupling reactions.

The amount of the metal compound to be used is preferably 0.0001 to 10moles, more preferably 0.001 to 3 moles, and even more preferably 0.01to 1 mole, relative to 1 mole of compound (a).

Examples of a halogen molecule X₂ include fluorine, chlorine, bromine,and iodine molecules, with an iodine molecule being preferred. Thehalogen molecule X₂ is preferably used in an equimolar to slightly molarexcess amount, relative to 1 mole of compound (a).

The reaction is preferably performed in the temperature range of −80° C.to 200° C., more preferably in the temperature range of −50° C. to 100°C., and particularly preferably in the temperature range of −20° C. to80° C. Although the reaction is desirably performed under normalpressure, it may be operated under elevated or reduced pressure in somecases. Moreover, the reaction may be accomplished in a continuous orbatch mode through one or more steps.

As a reaction solvent, an aliphatic or aromatic solvent may be used, asexemplified by ethers (e.g., tetrahydrofuran, diethyl ether);halogenated hydrocarbons (e.g., methylene chloride); halogenatedaromatic hydrocarbons (e.g., o-dichlorobenzene); amides (e.g.,N,N-dimethylformamide), sulfoxides (e.g., dimethyl sulfoxide).Alternatively, an aromatic hydrocarbon such as benzene, toluene orxylene may be used as an aromatic solvent.

Next, compound (b) is treated with a lithiating agent, followed bycoupling reaction with compound (c) in the presence of a metal compoundto obtain compound (d).

During the above reaction, compound (d) can be obtained when compound(c) is reacted in an equimolar to slightly molar excess amount, relativeto 1 mole of compound (b). Compound (c) is known and can be easilysynthesized by referring to, e.g., Takahashi et al., J. Am. Chem. Soc.,2002, 124 (4), pp 576. Alternatively, a commercially available productmay also be used.

As a lithiating agent, preferred is a C₁-C₂₀ hydrocarbon lithium such asalkyllithium, aryllithium, etc. For example, preferred for use is aC₁-C₆ alkyllithium such as butyllithium or a C₆-C₂₀ aryllithium such asphenyllithium.

As a metal compound, any of the same metal compounds as listed above maybe used. Among them, preferred are metal salts such as CuX, NiX₂, PdX₂,ZnX₂, CrX₂, CrX₃, CoX₂ or BiX₃ (wherein X represents a halogen atom suchas a chlorine atom, a bromine atom, etc.). The amount of the metalcompound to be used is preferably 0.01 to 100 moles, more preferably 0.1to 10 moles, and even more preferably 0.1 to 3 moles, relative to 1 moleof the dilithiated form.

This coupling reaction may preferably be accomplished in the presence ofa stabilizing agent such as N,N′-dimethylpropyleneurea,hexamethylphosphoamide, etc. The amount of the stabilizing agent to beused is preferably 0.01 to 100 moles, more preferably 0.1 to 10 moles,and even more preferably 0.1 to 3 moles, relative to 1 mole of thedilithiated form.

The reaction temperature is preferably −80° C. to 200° C., morepreferably −50° C. to 100° C., and even more preferably −20° C. to 80°C. Moreover, although the reaction is desirably performed under normalpressure, it may be operated under elevated or reduced pressure in somecases. The reaction may be accomplished in a continuous or batch modethrough one or more steps. As a reaction solvent, an aliphatic oraromatic solvent may be used. For specific examples of the reactionsolvent, reference may be made to those illustrated in the above step.

Subsequently, compound (d) is treated with a halogenating agent toobtain compound (e) according to the present invention.

A halogenating agent may be exemplified by N-chlorosuccinimide (NCS),N-bromosuccinimide (NBS), N-iodosuccinimide (NIS), iodine monochloride,etc.

The reaction temperature is preferably −78° C. to 150° C., morepreferably −78° C. to 50° C., and even more preferably −78° C. to 30° C.Moreover, although the reaction is desirably performed under normalpressure, it may be operated under elevated or reduced pressure in somecases. As a reaction solvent, an aliphatic or aromatic solvent may beused. For specific examples of the reaction solvent, reference may bemade to those illustrated in the above step.

For example, compound (e) can be obtained when the halogenating agent isreacted in an equimolar to slightly molar excess amount, relative to 1mole of compound (d), in a solvent such as dichloromethane.

After completion of the reaction in each step, the reaction mixture mayoptionally be treated by isolation and purification techniques used incommon organic synthesis reactions to thereby obtain the desiredcompound in each step.

[2] Method for producing a 6,13-substituted 5,14-dihydropentacenederivative

Next, an explanation will be given of the method of the presentinvention for producing a 6,13-substituted 5,14-dihydropentacenederivative. The method of the present invention for producing a6,13-substituted 5,14-dihydropentacene derivative is a method forproducing a 6,13-substituted 5,14-dihydropentacene derivativerepresented by the following formula (II):

[wherein A¹ and A², which may be the same or different, are eachindependently an optionally substituted C₁-C₂₀ hydrocarbon group; anoptionally substituted heteroaryl group; an optionally substitutedC₁-C₂₀ alkoxy group; an optionally substituted C₆-C₂₀ aryloxy group; anoptionally substituted C₁-C₂₀ alkoxycarbonyl group; an optionallysubstituted C₆-C₂₀ aryloxycarbonyl group; an optionally substitutedcarbamoyl group; an optionally substituted amino group or an optionallysubstituted silyl group, wherein if the hydrocarbon group, theheteroaryl group, the alkoxy group, the aryloxy group, thealkoxycarbonyl group, the aryloxycarbonyl group, the carbamoyl group,the amino group or the silyl group has a substituent(s), thesubstituent(s) is/are selected from the group consisting of a C₁-C₁₀hydrocarbon group, a C₁-C₁₀ alkoxy group, a C₆-C₁₂ aryloxy group, anamino group, a hydroxyl group, a halogen atom and a silyl group, and

R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰, which may be the same ordifferent, are each independently a hydrogen atom; an optionallysubstituted C₁-C₂₀ hydrocarbon group; an optionally substituted C₁-C₂₀alkoxy group; an optionally substituted C₆-C₂₀ aryloxy group; anoptionally substituted C₁-C₂₀ alkoxycarbonyl group; an optionallysubstituted C₆-C₂₀ aryloxycarbonyl group; an optionally substitutedcarbamoyl group; an optionally substituted amino group or an optionallysubstituted silyl group, wherein if the hydrocarbon group, the alkoxygroup, the aryloxy group, the alkoxycarbonyl group, the aryloxycarbonylgroup, the carbamoyl group, the amino group or the silyl group has asubstituent(s), the substituent(s) is/are selected from the groupconsisting of a C₁-C₁₀ hydrocarbon group, a C₁-C₁₀ alkoxy group, aC₆-C₁₂ aryloxy group, an amino group, a hydroxyl group, a halogen atomand a silyl group],

said method comprising the step of reacting a6,13-dihalogen-5,14-dihydropentacene derivative represented by thefollowing formula (I):

[wherein X¹ and X², which may be the same or different, are eachindependently a halogen atom, and R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ andR¹⁰ are the same as defined in formula (II)]with an organometallic compound comprising A¹ or A² as defined informula (II) in the presence of a transition metal catalyst.

As described above, in the present invention, a6,13-dihalogen-5,14-dihydropentacene derivative represented by formula(I) is reacted with an organometallic compound comprising A¹ or A²through coupling reaction in the presence of a transition metal catalystto thereby produce a desired compound (i.e., a compound represented byformula (II)). As a 6,13-dihalogen-5,14-dihydropentacene derivativerepresented by formula (I), those illustrated above in “A.6,13-Dihalogen-5,14-dihydropentacene derivative” can be used.

Any organometallic compound comprising A¹ or A² may be used as long asit is capable of providing A¹ and A² at the 6- and 13-positions,respectively, of the compound represented by formula (I) throughcross-coupling reaction, and such an organometallic compound alsoencompasses compounds of semi-metals such as silicon and boron. Examplesinclude organolithium compounds, organomagnesium compounds,organoaluminum compounds, organozinc compounds, organoboron compoundsand organosilyl compounds, etc.

For example, as an organometallic compound comprising A¹ or A² for usein this reaction, compounds represented by the following formulae (1) to(6) are preferred for use:RLi  (1)RMgY  (2)R₃Al  (3)RZnY  (4)RBY₂  (5)RSiR′₃  (6)[wherein each R, which may be the same or different, is independently A¹or A² as defined in formula (II), each Y, which may be the same ordifferent, is independently a halogen atom or a hydroxy group, and R′ isa C₁-C₁₀ alkyl group].

Among these compounds, R₃Al, RZnCl, RMgBr, RB(OH)₂, RSi(CH₃)₃ orRSi(CH(CH₃)₂)₃ is particularly preferred for use as an organometalliccompound. These organometallic compounds comprising A¹ or A² may be usedeither alone or in combination, as long as the object of the presentinvention is not impaired. When the substituents A¹ and A² to beintroduced are of different types, it is preferable to use anorganometallic compound comprising A¹ and an organometallic compoundcomprising A².

During the above reaction, the desired compound (i.e., the compoundrepresented by formula (II)) can be obtained when the organometalliccompound is reacted in an equal to slightly excess amount (preferably 1to 10 equivalents, more preferably 1 to 5 equivalents), relative to 1mole of the compound represented by formula (I).

The above reaction is accomplished in the presence of a catalystcontaining a catalytic amount of a transition metal (e.g., Pd, Cu, Ni orW) (i.e., a transition metal catalyst). As a transition metal catalyst,preferred is a Pd(0) organic complex, a Pd(II) salt or an organiccomplex thereof. Specific examples include palladium/carbon,tetrakis(triphenylphosphine)palladium, palladium(II) chloride,dichlorobis(triphenylphosphine)nickel(II),dichlorobis(triphenylphosphine)palladium(II),dichloro(2,2′-bipyridine)nickel and so on.

The amount of the transition metal catalyst to be used is preferably 0.5moles or less, more preferably 0.0001 to 0.5 moles, and even morepreferably 0.001 to 0.2 moles, relative to 1 mole of the compoundrepresented by formula (I).

The reaction temperature is preferably −80° C. to 200° C., morepreferably −50° C. to 100° C., and even more preferably −20° C. to 80°C. Moreover, although the reaction is desirably performed under normalpressure, it may be operated under elevated or reduced pressure in somecases. The reaction may be accomplished in a continuous or batch modethrough one or more steps.

As a reaction solvent, an aliphatic or aromatic solvent may be used, asexemplified by ethers (e.g., tetrahydrofuran, diethyl ether);halogenated hydrocarbons (e.g., methylene chloride); halogenatedaromatic hydrocarbons (e.g., o-dichlorobenzene); amides (e.g.,N,N-dimethylformamide), sulfoxides (e.g., dimethyl sulfoxide).Alternatively, an aromatic hydrocarbon such as benzene, toluene orxylene may be used as an aromatic solvent.

After completion of the reaction, the reaction mixture may optionally betreated by isolation and purification techniques used in common organicsynthesis reactions to thereby obtain the desired compound, i.e., a6,13-substituted 5,14-dihydropentacene derivative. This 6,13-substituted5,14-dihydropentacene derivative may be aromatized in a routine manner,as described later, to thereby easily obtain a 6,13-substitutedpentacene derivative.

According to the present invention, the desired compound can be obtainedwith high selectivity by means of characteristics of cross-couplingreaction.

In one embodiment of the present invention, it is preferred that A¹ andA², which may be the same or different, are each independently anoptionally substituted C₁-C₂₀ alkyl group, an optionally substitutedC₂-C₂₀ alkenyl group, an optionally substituted C₂-C₂₀ alkynyl group, anoptionally substituted C₆-C₂₀ aryl group or an optionally substitutedheteroaryl group.

Moreover, in one embodiment of the present invention, it is preferredthat X¹ and X² are each an iodine atom.

Further, in one embodiment of the present invention, it is preferredthat R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰, which may be the sameor different, are each independently a hydrogen atom; an optionallysubstituted C₁-C₂₀ alkyl group; an optionally substituted C₆-C₂₀ arylgroup or an optionally substituted silyl group.

Furthermore, in one embodiment of the present invention, it is preferredthat R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰ are each a hydrogenatom.

In one embodiment of the present invention, the above6,13-dihalogen-5,14-dihydropentacene derivative represented by formula(I) may be reacted with an organometallic complex to form a complexcompound represented by formula (IV) shown below, followed by reactionwith an organometallic compound comprising A¹ or A² to produce thedesired compound:

[wherein X¹ and X², which may be the same or different, are eachindependently a halogen atom, R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ andR¹⁰, which may be the same or different, are each independently ahydrogen atom; an optionally substituted C₁-C₂₀ hydrocarbon group; anoptionally substituted C₁-C₂₀ alkoxy group; an optionally substitutedC₆-C₂₀ aryloxy group; an optionally substituted C₁-C₂₀ alkoxycarbonylgroup; an optionally substituted C₆-C₂₀ aryloxycarbonyl group; anoptionally substituted carbamoyl group; an optionally substituted aminogroup or an optionally substituted silyl group, wherein if thehydrocarbon group, the alkoxy group, the aryloxy group, thealkoxycarbonyl group, the aryloxycarbonyl group, the carbamoyl group,the amino group or the silyl group has a substituent(s), thesubstituent(s) is/are selected from the group consisting of a C₁-C₁₀hydrocarbon group, a C₁-C₁₀ alkoxy group, a C₆-C₁₂ aryloxy group, anamino group, a hydroxyl group, a halogen atom and a silyl group, andR^(a) and R^(b), which may be the same or different, are eachindependently a C₁-C₂₀ alkyl group or a C₆-C₂₀ aryl group].

As an organometallic complex, preferred is a Pd(0) organic complex, aPd(II) salt or an organic complex thereof. Examples preferably includetetrakis(triphenylphosphine)palladium,dichlorobis(triphenylphosphine)palladium(II) and so on.

A desired compound (i.e., a compound represented by formula (IV)) can beobtained when the organometallic complex is reacted in an equal toslightly excess amount, relative to 1 mole of the compound representedby formula (I). Moreover, the resulting compound may further be reactedwith, e.g., trialkylphosphine or triarylphosphine to thereby obtain adesired compound (i.e., a compound represented by formula (IV)).

As a reaction solvent, an aliphatic or aromatic solvent may be used, asexemplified by ethers (e.g., tetrahydrofuran, diethyl ether);halogenated hydrocarbons (e.g., methylene chloride); halogenatedaromatic hydrocarbons (e.g., o-dichlorobenzene); amides (e.g.,N,N-dimethylformamide), sulfoxides (e.g., dimethyl sulfoxide).Alternatively, an aromatic hydrocarbon such as benzene, toluene orxylene may be used as an aromatic solvent.

After completion of the reaction, the reaction mixture may optionally betreated by isolation and purification techniques used in common organicsynthesis reactions to thereby obtain the desired compound (i.e., thecompound represented by formula (IV)).

The resulting compound represented by formula (IV) may be reacted withan organometallic compound comprising A¹ or A² as described abovethrough cross-coupling reaction to thereby obtain the 6,13-substituted5,14-dihydropentacene derivative represented by formula (II).

The amount of the organometallic compound comprising A¹ or A² to be usedis preferably an equal to slightly excess amount relative to 1 mole ofthe compound represented by formula (IV), more preferably 1 to 10equivalents, and even more preferably 1 to 5 equivalents.

As a reaction solvent, the same solvent as used in the above reactionmay also be used in this reaction.

[3] Method for producing a 6,13-substituted pentacene derivative

Next, an explanation will be given of the method of the presentinvention for producing a 6,13-substituted pentacene derivative. Themethod of the present invention for producing a 6,13-substitutedpentacene derivative is a method for producing a 6,13-substitutedpentacene derivative represented by the following formula

[wherein A¹ and A², which may be the same or different, are eachindependently an optionally substituted C₁-C₂₀ hydrocarbon group; anoptionally substituted C₁-C₂₀ alkoxy group; an optionally substitutedC₆-C₂₀ aryloxy group; an optionally substituted C₁-C₂₀ alkoxycarbonylgroup; an optionally substituted C₆-C₂₀ aryloxycarbonyl group; anoptionally substituted carbamoyl group; an optionally substituted aminogroup or an optionally substituted silyl group, wherein if thehydrocarbon group, the alkoxy group, the aryloxy group, the amino groupor the silyl group has a substituent(s), the substituent(s) is/areselected from the group consisting of a C₁-C₁₀ hydrocarbon group, aC₁-C₁₀ alkoxy group, a C₆-C₁₂ aryloxy group, an alkoxycarbonyl group, anaryloxycarbonyl group, a carbamoyl group, an amino group, a hydroxylgroup, a halogen atom and a silyl group, and

R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰, which may be the same ordifferent, are each independently a hydrogen atom; an optionallysubstituted C₁-C₂₀ hydrocarbon group; an optionally substituted C₁-C₂₀alkoxy group; an optionally substituted C₆-C₂₀ aryloxy group; anoptionally substituted C₁-C₂₀ alkoxycarbonyl group; an optionallysubstituted C₆-C₂₀ aryloxycarbonyl group; an optionally substitutedcarbamoyl group; an optionally substituted amino group or an optionallysubstituted silyl group, wherein if the hydrocarbon group, the alkoxygroup, the aryloxy group, the alkoxycarbonyl group, the aryloxycarbonylgroup, the carbamoyl group, the amino group or the silyl group has asubstituent(s), the substituent(s) is/are selected from the groupconsisting of a C₁-C₁₀ hydrocarbon group, a C₁-C₁₀ alkoxy group, aC₆-C₁₂ aryloxy group, an amino group, a hydroxyl group, a halogen atomand a silyl group],

said method comprising the steps of:

reacting a 6,13-dihalogen-5,14-dihydropentacene derivative representedby the following formula (I):

[wherein X¹ and X², which may be the same or different, are eachindependently a halogen atom, and R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ andR¹⁰ are the same as defined in formula (III)]with an organometallic compound comprising A¹ or A² as defined informula (III) in the presence of a transition metal catalyst; and

aromatizing the compound obtained in the above step in the presence of adehydrogenation reagent.

The step of reacting a 6,13-dihalogen-5,14-dihydropentacene derivativerepresented by formula (I) with an organometallic compound comprising A¹or A² is as described above in “B. Method for producing a6,13-substituted 5,14-dihydropentacene derivative.”

In the present invention, a desired pentacene derivative whose 6- and13-positions are substituted can be obtained when the 6,13-substituted5,14-dihydropentacene derivative represented by formula (II) obtained inthe above step is aromatized in the presence of a dehydrogenationreagent.

In one embodiment of the present invention, it is preferred that alithiating agent is used as a dehydrogenation reagent.

As a lithiating agent, preferred is a C₁-C₂₀ hydrocarbon lithium such asalkyllithium, aryllithium, etc. For example, preferred for use is aC₁-C₆ alkyllithium such as butyllithium or a C₆-C₂₀ aryllithium such asphenyllithium. Such a lithiating agent is used in an amount ofpreferably 0.1 to 10 equivalents, more preferably 0.5 to 5 equivalents,and even more preferably 1 to 3 equivalents of the above compoundrepresented by formula (II).

The lithiating agent is preferably used together with an activator forthe lithiating agent. Preferred activators are tertiary amines includingN,N,N′,N′-tetraalkylalkylenectiamines such asN,N,N′,Nt-tetramethylethylenediamine (TMEDA). An alkyllithium appears tobe present in the form of an oligomer such as a tetramer in a solution.In the presence of a tertiary amine, nitrogen atoms in the amine will becoordinated to the lithium atom in the alkyllithium to thereby disruptthe oligomer structure. As a result of this, the lithium atom in thealkyllithium will be exposed to the solution, resulting in improvedreactivity. The amount of the activator to be used may be determined asappropriate, depending on the type thereof, etc.

As a reaction solvent, a nonpolar organic solvent is preferably used.For example, an alkane (e.g., hexane) or an aromatic compound (e.g.,benzene) is preferred for use.

The reaction temperature is preferably 0° C. to 200° C., more preferably20° C. to 100° C., and even more preferably 30° C. to 80° C.

In another embodiment of the present invention, a quinone compoundrepresented by the following formula is used as the abovedehydrogenation reagent:

[wherein X¹, X², X³ and X⁴, which may be the same or different, are eachindependently a halogen atom or a cyano group].

For example, X¹, X², X³ and X⁴ may each be a chlorine atom. Namely, theabove quinone compound may be chloranil. Alternatively, X¹ and X² mayeach be a cyano group, while X³ and X⁴ may each be a chlorine atom.Namely, the above quinone compound may be2,3-dichloro-5,6-dicyanoquinone. X¹, X², X³ and X⁴ may each be a cyanogroup. Namely, the above quinone compound may be2,3,5,6-tetracyanoquinone.

To prevent such by-product formation, the above quinone compound is usedin an amount of preferably 0.9 to 1.2 equivalents, more preferably 0.9to 1.15 equivalents, and even more preferably 0.95 to 1.05 equivalentsof the above compound represented by formula (II).

As a reaction solvent, preferred is an aromatic compound such asbenzene.

The reaction temperature is preferably −80° C. to 200° C., morepreferably 0° C. to 100° C., and even more preferably 10° C. to 80° C.If desired, the reaction may be allowed to proceed under light shieldingconditions.

In yet another embodiment of the present invention, the abovedehydrogenation reagent preferably comprises palladium. For example,palladium supported on carbon (e.g., activated carbon), which iscommercially available as so-called palladium on carbon, may preferablybe used for this purpose. Pd/C is a catalyst widely used fordehydrogenation and may also be used in the present invention as inconventional cases. The reaction temperature is 200° C. to 500° C., byway of example. It should be noted that the reaction temperature may bedetermined as appropriate, depending on various conditions such asstarting materials, etc.

After completion of the reaction, the reaction mixture may optionally betreated by isolation and purification techniques used in common organicsynthesis reactions to thereby obtain the desired compound, i.e., a6,13-substituted pentacene derivative. For details of the aromatizationstep, reference may be made to WO01/064611 and JP 2004-331534A.

EXAMPLES

The present invention will be further described by way of the followingexamples, which are not intended to limit the scope of the presentinvention.

All the reactions were performed under a nitrogen atmosphere, unlessotherwise specified. Tetrahydrofuran (THF) was dried over asodium/benzophenone system before use. Commercially available reagentswere used directly without purification, unless otherwise specified. NMRyields were each determined by using mesitylene as an internal standard.

Example 1 Preparation of 6,13-diiodo-5,14-dihydropentacene derivative(1) Step 1: Preparation of2,3-bis-(iodotrimethylsilylmethylene)-1,2,3,4-tetrahydronaphthalene

Bis(η⁵-cyclopentadienyl)dichlorozirconium (365 mg, 1.25 mmol) wasdissolved in THF (15 ml). To this solution, n-butyllithium (1.56 M inhexane, 1.60 mL, 2.5 mmol) was added at −78° C., and this mixture wasstirred for 15 minutes. The resulting solution was kept at −40° C. for30 minutes and then cooled again to −78° C. After 15 minutes passed,this solution was mixed with compound 1 (298 mg, 1.0 mmol) and returnedto room temperature. After stirring for 3 hours, the reaction mixturewas mixed with CuCl (99 mg, 1.0 mmol) and I₂ (508 mg, 2.0 mmol) at 0°C., returned again to room temperature and then allowed to stand for 3hours. After cooling to 0° C., the resulting reaction mixture wasquenched with 3 N HCl, and the reaction product was extracted with ethylacetate. The organic layer was washed with water, saturated aqueoussodium bicarbonate and aqueous sodium chloride, and then dried overanhydrous magnesium sulfate. After distilling off the solvent, theresulting brown viscous oil was purified by silica gel chromatography(hexane:triethylamine=100:1) to give the titled compound (compound 2) asa light-yellow solid (397 mg, yield: 72%).

2: ¹H NMR (CDCl₃, Me₄Si) δ: 0.33 (s, 18H), 3.60 (d, J=16.5 Hz, 2H), 3.91(d, J=16.5 Hz, 2H), 7.04-7.07 (m, 2H), 7.15-7.18 (m, 2H); ¹³C NMR(CDCl₃, Me₄Si) δ: 1.7, 38.5, 104.9, 126.5, 128.3, 135.8, 160.3

Step 2: Preparation of 6,13-bis(trimethylsilyl)-5,14-dihydropentacene

Compound 2 obtained in step 1 (552 mg, 1.0 mmol) was dissolved in THF(15 ml). To this solution, t-butyllithium (1.76 M in n-pentane, 2.27 mL,4.0 mmol) was slowly added at −78° C., and this mixture was stirred for15 minutes. The resulting solution was kept at −40° C. for 30 minutesand then cooled again to −78° C. After 15 minutes passed, this solutionwas mixed with CuCl (198 mg, 2.0 mmol) and DMPU (0.36 mL, 3.0 mmol),followed by stirring at 0° C. for 0.5 hours. Then, to this reactionmixture, 2,3-diiodonaphthalene (760 mg, 2.0 mmol) was added and heatedat 50° C. for 12 hours. The reaction mixture was cooled to 0° C. andthen quenched with 3 N HCl, and the reaction product was extracted withhexane. The organic layer was washed with saturated aqueous sodiumbicarbonate and aqueous sodium chloride, and then dried over anhydrousmagnesium sulfate. The resulting solution was concentrated under reducedpressure, and the residue was purified by silica gel chromatography(hexane:ethyl acetate:triethylamine=50:1:1) to give the titled compound(compound 3) as a yellow solid (169 mg, yield: 40%).

3: ¹H NMR (CDCl₃, Me₄Si) δ: 0.70 (s, 18H), 4.21 (s, 4H), 7.20-7.23 (m,2H), 7.32-7.35 (m, 2H), 7.41-7.44 (m, 2H), 7.92-7.96 (m, 2H), 8.69 (s,2H); ¹³C NMR (CDCl₃, Me₄Si) δ: 4.3, 39.2, 125.0, 126.5, 126.6, 126.9,128.0, 130.1, 134.7, 135.5, 138.1, 143.9;

HRMS (EI) C₂₈H₃₂Si₂: Calculated: 424.2043. Found: 424.2037.

Step 3: Preparation of 6,13-diiodo-5,14-dihydropentacene derivative

Compound 3 obtained in step 2 (424 mg, 1.0 mmol) was dissolved indichloromethane (5 mL). To this solution, ICI (1.0 M in dichloromethane,2.0 mL, 2.0 mmol) was slowly added at −78° C. After stirring at −78° C.for 3 hours, the resulting reaction mixture was quenched with saturatedaqueous sodium thiosulfate, and the reaction product was extracted withchloroform. The organic layer was washed with aqueous sodium chloride.After removal of the solvent, the residue was washed with methanol. Thegenerated precipitates were recovered, and the residue was purified bysilica gel chromatography (chloroform) to give the titled compound(compound 4) as a brown liquid (119 mg, yield: 23%).

4: ¹H NMR (CDCl₃, Me₄Si) δ: 4.47 (s, 4H), 7.25-7.29 (m, 2H), 7.43-7.44(m, 2H), 7.52-7.55 (m, 2H), 8.09-8.12 (m, 2H), 8.85 (s, 2H); ¹³C NMR(CDCl₃, Me₄Si) δ: 45.5, 106.7, 126.5, 126.9, 127.2, 128.1, 132.1, 132.8,133.0, 136.3, 139.8;

HRMS (EI) C₂₂H₁₄I₂: Calculated: 531.9185. Found: 531.9199.

Example 2 Preparation of 6,13-diiodo-5,14-dihydropentacene derivative(2)

The same procedure as shown in Example 1 was repeated using asubstituted diiododiene and a substituted diiodonaphthalene, resultingin a 6,13-diiodo-5,14-dihydropentacene derivative having eightsubstituents. The yield was 20%.

6: ¹H NMR (C₆D₆) δ: 1.03 (t, J=7 Hz, 6H), 1.06 (t, J=7 Hz, 6H), 1.22 (t,J=7 Hz, 6H), 1.29 (t, J=7 Hz, 6H), 1.63-1.76 (m, 12H), 1.97-2.01 (m,4H), 2.67-2.71 (m, 4H), 2.84-2.94 (m, 8H), 3.33-3.37 (m, 4H), 4.31 (s,4H), 9.28 (s, 2H); ¹³C NMR (C₆D₆) δ: 15.21, 15.24, 15.4, 15.5, 24.9,25.3, 25.6, 25.7, 32.3, 32.71, 32.74, 33.3, 42.6, 106.6, 130.6, 131.5,131.9, 133.9, 134.4, 135.4, 137.1, 137.8, 141.5;

HRMS (EI) Calculated: C₄₆H₆₂I₂: 868.2941. Found: 868.2947.

Example 3 Preparation of 6,13-dimethyl-5,14-dihydropentacene

Compound 4 obtained in Example 1 (161 mg, 0.30 mmol) and PdCl₂(PPh₃)₂(10 mg, 0.0015 mmol) were dissolved in THF (10 mL). To this solution,Me₃Al (1.0 M in hexane, 1.2 mL, 1.2 mmol) was added, and the resultingmixture was heated under reflux for 1 hour. The reaction mixture wascooled to room temperature and then quenched with 3 N HCl, and thereaction product was extracted with chloroform. After removal of thesolvent, the residue was purified by silica gel chromatography(hexane:ethyl acetate=10:1) to give the titled compound (compound 7) asa light-yellow solid (76 mg, isolated yield: 82%).

7: ¹H NMR (CDCl₃, Me₄Si, 600 MHz) δ: 2.78 (s, 6H), 4.10 (s, 4H),7.14-7.16 (m, 2H), 7.28-7.30 (m, 2H), 7.34-7.36 (m, 2H), 7.92-7.93 (m,2H), 8.50 (s, 2H); ¹³C NMR (CDCl₃, Me₄Si) δ: 15.1, 34.4, 123.0, 125.1,126.4, 127.1, 127.3, 128.3, 130.8, 131.0, 132.6, 137.3.

HRMS (EI) C₂₄H₂₀: Calculated: 308.1565. Found: 308.1565.

Example 4 Preparation of 6,13-diethyl-5,14-dihydropentacene

The same reaction as conducted in Example 3 was repeated except forusing Et₃Al instead of Me₃Al, resulting in the titled compound (compound8) as a yellow solid (NMR yield: 74%, isolated yield: 65%).

8: ¹H NMR (CDCl₃, Me₄Si, 600 MHz) δ: 1.40 (t, J=7 Hz, 6H), 3.38 (q,J1,2=7.8 Hz, J1,3=15.6 Hz, 4H), 4.15 (s, 4H), 7.22-7.23 (m, 2H),7.37-7.38 (m, 2H), 7.41-7.43 (m, 2H), 8.00-8.01 (m, 2H), 8.62 (s, 2H);¹³C NMR (CDCl₃, Me₄Si) δ: 15.0, 22.0, 34.0, 122.9, 125.0, 126.5, 127.0,128.4, 129.9, 131.0, 132.4, 133.4, 137.9.

HRMS (EI) C₂₆H₂₄: Calculated: 336.1878. Found: 336.1868.

Example 5 Preparation of 6,13-diphenyl-5,14-dihydropentacene

Aryllithium (0.2 mL, 0.4 mmol) and dry zinc chloride (52 mg, 0.4 mmol)were reacted in THF (2 mL) to prepare an arylzinc reagent. To thearylzinc reagent thus prepared, compound 4 obtained in Example 1 (50 mg,0.09 mmol) and a palladium(0) catalyst (Pd(PPh₃)₄, 5 mg, 0.0045 mmol)were then added, and this mixture was heated at 50° C. for 15 hours. Thereaction mixture was cooled to room temperature and then quenched with 3N HCl, and the reaction product was extracted with chloroform. Theorganic layer was washed with water, saturated aqueous sodiumbicarbonate and aqueous sodium chloride, and then dried over anhydrousmagnesium sulfate. The solvent was distilled off under reduced pressure,and the resulting residue was purified by GPC to give the titledcompound (compound 9) as a yellow solid (13 mg, yield: 34%).

9: ¹H NMR (CDCl₃, Me₄Si, 400 MHz)) δ: 3.87 (s, 4H), 7.14 (s, 4H),7.30-7.33 (m, 2H), 7.44-7.46 (m, 4H), 7.56-7.66 (m, 6H), 7.75-7.77 (m,2H), 7.97 (s, 2H); ¹³C NMR (CDCl₃, Me₄Si) δ: 35.5, 125.2, 125.3, 126.4,127.1, 127.5, 128.3, 128.8 (two peaks were overlapped), 130.7, 130.8(two peaks were overlapped), 131.0, 133.1, 136.0, 137.7, 139.8.

HRMS (EI) C₃₄H₂₄: Calculated: 432.1878. Found: 432.1881.

Example 6 Preparation of 6,13-substituted 5,14-dihydropentacenederivative

The same procedures as shown in Examples 3 to 5 were repeated except forusing the conditions indicated in Table 1 to prepare 6,13-substituted5,14-dihydropentacene derivatives (compound 10).

TABLE 1 Amount Yield Ex- used Reaction of 10 ample Reagent R—M (eq.)[Pd] conditions (%)* a Me₃Al 3.0 Pd(PPh₃)₄ refluxing, 86 1 d (82) bEt₃Al 3.0 Pd(PPh₃)₄ refluxing, 84 1 d (75) c

3.0 Pd(PPh₃)₄ refluxing, 12 h 74 (70) d

3.0 Pd(PPh₃)₄ 50° C., 12 h 94 (72) e

3.0 Pd(PPh₃)₄ 50° C., 12 h 86 (70) f

5.0 Pd(PPh₃)₄ CuI, Et₃N, 50° C., 6 h 92 (84) g

5.0 Pd(PPh₃)₄ CuI, Et₃N, 50° C., 6 h 96 (87) h

3.0 Pd(PPh₃)₄ NaOH, refluxing, 3 d 80 (73) *NMR yield with isolatedyield in parentheses

Example 7 Reaction of 6,13-diiodo-5,14-dihydropentacene derivative withpalladium complex

Compound 4 obtained in Example 1 (1 mmol) and Pd(PPh₃)₄ (1.2 mmol) wereadded to THF (10 ml), and this mixture was reacted at room temperaturefor 12 hours. The reaction product was diluted with hexane toprecipitate a complex, which was then isolated by filtration and driedto give complex compound 11 (NMR yield: 79%, isolated yield: 41%).

Then, to the resulting complex compound 11 (1 mmol), trimethylphosphine(4 mmol) was added and reacted at room temperature for 12 hours. Whenthe reaction product was diluted with hexane and allowed to stand,crystals were precipitated, which were then filtered and dried to givecomplex compound 12. FIG. 1 shows the results of X-ray structuralanalysis obtained for complex compound 12.

Example 8 Preparation of 6,13-substituted 5,14-dihydropentacenederivative

In accordance with the conditions indicated in Table 2, 6,13-substituted5,14-dihydropentacene derivatives (compound 13) were prepared.

TABLE 2 Amount Yield used Reaction of 13 Example Reagent R—M (eq.)conditions (%)* i Me₃Al 3.0 refluxing, 99 12 h j Et₃Al 3.0 refluxing, 9212 h k

4.0 refluxing, 12 h 99 l

4.0 refluxing, 12 h 95 m

4.0 refluxing, 12 h 98 n

5.0 CuI, Et₃N, refluxing, 12 h 96 o

5.0 CuI, Et₃N, refluxing, 1 d 100 *NMR yield

As shown above, desired 6,13-substituted 5,14-dihydropentacenederivatives were obtained when the 6,13-diiodo-5,14-dihydropentacenederivative was reacted with a palladium complex and the resultingcomplex compound was then reacted with organometallic compounds. Sincethe above complex compound is stably present, it is useful as a reactionintermediate for production of 6,13-substituted 5,14-dihydropentacenederivatives.

INDUSTRIAL APPLICABILITY

The present invention provides a 6,13-dihalogen-5,14-dihydropentacenederivative, which is a novel compound. When using the compound of thepresent invention, it is possible to produce a 6,13-substituted5,14-dihydropentacene derivative and further a 6,13-substitutedpentacene derivative, etc., in a simpler manner with high selectivity.

The invention claimed is:
 1. A 6,13-dihalogen-5,14-dihydropentacenederivative represented by the following formula (I):

[wherein X¹ and X², which may be the same or different, are eachindependently a halogen atom, and R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ andR¹⁰, which may be the same or different, are each independently ahydrogen atom; an optionally substituted C₁-C₂₀ hydrocarbon group; anoptionally substituted C₁-C₂₀ alkoxy group; an optionally substitutedC₆-C₂₀ aryloxy group; an optionally substituted C₁-C₂₀ alkoxycarbonylgroup; an optionally substituted C₆-C₂₀ aryloxycarbonyl group; anoptionally substituted carbamoyl group; an optionally substituted aminogroup or an optionally substituted silyl group, wherein if thehydrocarbon group, the alkoxy group, the aryloxy group, thealkoxycarbonyl group, the aryloxycarbonyl group, the carbamoyl group,the amino group or the silyl group has a substituent(s), thesubstituent(s) is/are selected from the group consisting of a C₁-C₁₀hydrocarbon group, a C₁-C₁₀ alkoxy group, a C₆-C₁₂ aryloxy group, anamino group, a hydroxyl group, a halogen atom and a silyl group].
 2. Thederivative according to claim 1, wherein X¹ and X² are each an iodineatom.
 3. The derivative according to claim 1, wherein R¹, R², R³, R⁴,R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰, which may be the same or different, are eachindependently a hydrogen atom; an optionally substituted C₁-C₂₀ alkylgroup; an optionally substituted C₆-C₂₀ aryl group or an optionallysubstituted silyl group.
 4. The derivative according to claim 1, whereinR¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰ are each a hydrogen atom. 5.A method for producing a 6,13-substituted 5,14-dihydropentacenederivative represented by the following formula (II):

[wherein A¹ and A², which may be the same or different, are eachindependently an optionally substituted C₁-C₂₀ hydrocarbon group; anoptionally substituted heteroaryl group; an optionally substitutedC₁-C₂₀ alkoxy group; an optionally substituted C₆-C₂₀ aryloxy group; anoptionally substituted C₁-C₂₀ alkoxycarbonyl group; an optionallysubstituted C₆-C₂₀ aryloxycarbonyl group; an optionally substitutedcarbamoyl group; an optionally substituted amino group or an optionallysubstituted silyl group, wherein if the hydrocarbon group, theheteroaryl group, the alkoxy group, the aryloxy group, thealkoxycarbonyl group, the aryloxycarbonyl group, the carbamoyl group,the amino group or the silyl group has a substituent(s), thesubstituent(s) is/are selected from the group consisting of a C₁-C₁₀hydrocarbon group, a C₁-C₁₀ alkoxy group, a C₆-C₁₂ aryloxy group, anamino group, a hydroxyl group, a halogen atom and a silyl group, and R¹,R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰, which may be the same ordifferent, are each independently a hydrogen atom; an optionallysubstituted C₁-C₂₀ hydrocarbon group; an optionally substituted C₁-C₂₀alkoxy group; an optionally substituted C₆-C₂₀ aryloxy group; anoptionally substituted C₁-C₂₀ alkoxycarbonyl group; an optionallysubstituted C₆-C₂₀ aryloxycarbonyl group; an optionally substitutedcarbamoyl group; an optionally substituted amino group or an optionallysubstituted silyl group, wherein if the hydrocarbon group, the alkoxygroup, the aryloxy group, the alkoxycarbonyl group, the aryloxycarbonylgroup, the carbamoyl group, the amino group or the silyl group has asubstituent(s), the substituent(s) is/are selected from the groupconsisting of a C₁-C₁₀ hydrocarbon group, a C₁-C₁₀ alkoxy group, aC₆-C₁₂ aryloxy group, an amino group, a hydroxyl group, a halogen atomand a silyl group], said method comprising the step of reacting a6,13-dihalogen-5,14-dihydropentacene derivative represented by thefollowing formula (I):

[wherein X¹ and X², which may be the same or different, are eachindependently a halogen atom, and R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ andR¹⁰ are the same as defined in formula (II)] with an organometalliccompound comprising A¹ or A² as defined in formula (II) in the presenceof a transition metal catalyst.
 6. The method according to claim 5,wherein the organometallic compound is selected from the groupconsisting of an organolithium compound, an organomagnesium compound, anorganoaluminum compound, an organozinc compound, an organoboron compoundand an organosilyl compound.
 7. The method according to claim 5, whereinthe organometallic compound is any of compounds represented by formulae(1) to (6):RLi  (1)RmgY  (2)R₃Al  (3)RznY  (4)RBY₂  (5)RSiR′₃  (6) [wherein each R, which may be the same or different, isindependently A¹ or A² as defined in formula (II), each Y, which may bethe same or different, is independently a halogen atom or a hydroxygroup, and R′ is a C₁-C₁₀ alkyl group].
 8. The method according to claim5, wherein the transition metal catalyst comprises a nickel complex or apalladium complex.
 9. The method according to claim 5, wherein A¹ andA², which may be the same or different, are each independently anoptionally substituted C₁-C₂₀ alkyl group, an optionally substitutedC₂-C₂₀ alkenyl group, an optionally substituted C₂-C₂₀ alkynyl group, anoptionally substituted C₆-C₂₀ aryl group or an optionally substitutedheteroaryl group.
 10. The method according to claim 5, wherein X¹ and X²are each an iodine atom.
 11. The method according to claim 5, whereinR¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰, which may be the same ordifferent, are each independently a hydrogen atom; an optionallysubstituted C₁-C₂₀ alkyl group; an optionally substituted C₆-C₂₀ arylgroup or an optionally substituted silyl group.
 12. The method accordingto claim 5, wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰ are eacha hydrogen atom.
 13. A complex compound represented by the followingformula (IV):

[wherein X¹ and X², which may be the same or different, are eachindependently a halogen atom, R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ andR¹⁰, which may be the same or different, are each independently ahydrogen atom; an optionally substituted C₁-C₂₀ hydrocarbon group; anoptionally substituted C₁-C₂₀ alkoxy group; an optionally substitutedC₆-C₂₀ aryloxy group; an optionally substituted C₁-C₂₀ alkoxycarbonylgroup; an optionally substituted C₆-C₂₀ aryloxycarbonyl group; anoptionally substituted carbamoyl group; an optionally substituted aminogroup or an optionally substituted silyl group, wherein if thehydrocarbon group, the alkoxy group, the aryloxy group, thealkoxycarbonyl group, the aryloxycarbonyl group, the carbamoyl group,the amino group or the silyl group has a substituent(s), thesubstituent(s) is/are selected from the group consisting of a C₁-C₁₀hydrocarbon group, a C₁-C₁₀ alkoxy group, a C₆-C₁₂ aryloxy group, anamino group, a hydroxyl group, a halogen atom and a silyl group, andR^(a) and R^(b), which may be the same or different, are eachindependently an optionally substituted C₁-C₂₀ alkyl group or anoptionally substituted C₆-C₂₀ aryl group].
 14. A method for producing a6,13-substituted 5,14-dihydropentacene derivative represented by thefollowing formula (II):

[wherein A¹ and A², which may be the same or different, are eachindependently an optionally substituted C₁-C₂₀ hydrocarbon group; anoptionally substituted heteroaryl group; an optionally substitutedC₁-C₂₀ alkoxy group; an optionally substituted C₆-C₂₀ aryloxy group; anoptionally substituted C₁-C₂₀ alkoxycarbonyl group; an optionallysubstituted C₆-C₂₀ aryloxycarbonyl group; an optionally substitutedcarbamoyl group; an optionally substituted amino group or an optionallysubstituted silyl group, wherein if the hydrocarbon group, theheteroaryl group, the alkoxy group, the aryloxy group, thealkoxycarbonyl group, the aryloxycarbonyl group, the carbamoyl group,the amino group or the silyl group has a substituent(s), thesubstituent(s) is/are selected from the group consisting of a C₁-C₁₀hydrocarbon group, a C₁-C₁₀ alkoxy group, a C₆-C₁₂ aryloxy group, anamino group, a hydroxyl group, a halogen atom and a silyl group, and R¹,R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰, which may be the same ordifferent, are each independently a hydrogen atom; an optionallysubstituted C₁-C₂₀ hydrocarbon group; an optionally substituted C₁-C₂₀alkoxy group; an optionally substituted C₆-C₂₀ aryloxy group; anoptionally substituted C₁-C₂₀ alkoxycarbonyl group; an optionallysubstituted C₆-C₂₀ aryloxycarbonyl group; an optionally substitutedcarbamoyl group; an optionally substituted amino group or an optionallysubstituted silyl group, wherein if the hydrocarbon group, the alkoxygroup, the aryloxy group, the alkoxycarbonyl group, the aryloxycarbonylgroup, the carbamoyl group, the amino group or the silyl group has asubstituent(s), the substituent(s) is/are selected from the groupconsisting of a C₁-C₁₀ hydrocarbon group, a C₁-C₁₀ alkoxy group, aC₆-C₁₂ aryloxy group, an amino group, a hydroxyl group, a halogen atomand a silyl group], said method comprising the step of reacting acomplex compound represented by the following formula (IV):

[wherein X¹ and X², which may be the same or different, are eachindependently a halogen atom, R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰are the same as defined in formula (II), and R^(a) and R^(b), which maybe the same or different, are each independently an optionallysubstituted C₁-C₂₀ alkyl group or an optionally substituted C₆-C₂₀ arylgroup] with an organometallic compound comprising A¹ or A² as defined informula (II).